Method for the preparation of biodegradable glycidol surfactants

ABSTRACT

This invention relates to a novel method of preparing biodegradable glycidol surfactants by reacting selected aliphatic alcohols with glycidol in the presence of a polar, non-reactive, miscible solvent and to the surfactants produced by such method.

United States Patent Wojtowicz et a1.

1 1 Apr. 22, 1975 Conn.; Milton Lapkin. Barrington. R.1.

Assignee: Olin Corporation, New Haven.

Conn.

Filed: Jan. 10, 1973 Appl. N0.: 322,340

Related U.S. Application Data Continuation-in-part of Ser. No. 27.107. April 9. 1970. Pat. No. 3.719.636.

U.S. C1 260/615 B: 252/307; 252/351 Int. Cl. C07c 43/04 Field of Search 260/615 B References Cited UNITED STATES PATENTS 8/1937 Orthner ct a1. 11 260/615 R 2.131.142 9/1938 Orthner ct a1.l 260/615 BX 2.236.919 4/1941 Reynhart 260/615 B 2.. 0.185 7/1965 Marple ct a1... 260/615 B 2.723.294 11/1955 Bcnoit 260/615 B 2.782.240 2/1957 Hefner et a1. 260/615 B 2.807.651 9/1957 Britton et a1... 260/615 B 3.042.666 7/1962 Genthes 260/615 B 3.317.508 5/1967 Winquist ct a1.... 260/615 R 3.445.525 5/1968 Bormann ct a1 260/615 B Primary Eraminer-Howard T. Mars Attorney, Agem. or FirmR0bert L. Andersen; Eugene Zagarella. Jr.

[57] ABSTRACT This invention relates to a novel method of preparing biodegradable glycidol surfactants by reacting selected aliphatic alcohols with glycid-ol in the presence of a polar. non-reactive. miscible solvent and to the surfactants produced by such method.

7 Claims, No Drawings METHOD FOR THE PREPARATION OF BIODEGRADABLE GLYCIDOL SURFACTANTS This is a continuation-in-part of co-pending application Ser. No. 27.107.fi1ed Apr. 9. 1970. now L'.S. Pat. No. 3.719.636.

This invention relates to a novel method for preparing biodegradable glycidol surfactants by reacting selected aliphatic alcohols with glycidol in the presence of a polar. non-reactive. miscible solvent and to the surfactants produced by such method.

Previous methods of preparing surfactants derived from alkylphenols and glycidol have been described in US. Pat. Nos. 2.213.477 and 2.233.381. While. the surfactants produced by these methods are generally considered satisfactory. they are not biodegradable and are also not considered economically attractive. A1- though surfactants derived from glycidol and aliphatic alcohols have not been disclosed. US. Pat. No. 2.131.142 shows the oxyalkylation of aliphatic alcohols with glycidol followed by reaction with ethylene oxide. However. it was found that by using conditions similar to said US. Pat. No. 2.131.142. i.e. reacting aliphatic alcohol with glycidol. extremely low amounts of the alcohol are converted. resulting in poor yields. and even more significantly. the resulting products are too highly hydrophilic and exhibit properties which are not satisfactory (See Examples V to V11).

Now it has been found that by reacting selected aliphatic alcohols with glycidol in the presence ofselccted polar. non-reactive and miscible (with the alcohol. glycidol and reaction product) solvents. alcohol consumption is increased significantly. resulting in the formation of compounds having the general formula:

wherein R is a linear aliphatic hydrocarbon of 6 to 24 carbons. v is hydrogen or a hydroxyl group. and .v is 4 to 14.

The compounds formed by the method of this invention generally are used as biodegradable surfactants and more particularly. are useful. for example. as wetting agents. dispersing agents and foaming agents.

More particularly. this invention relates to the reaction of selected aliphatic alcohols with glycidol in the presence ofa polar. non-reactive. miscible solvent and a basic or acid catalyst as illustrated by the following equation wherein for instance. cetyl alcohol is reacted with 6 moles of glycidol in the presence of methyl ethyl ketone (MEK) and potassium hydroxide:

The aliphatic alcohols which are suitable for use in the method ofthis invention are shown by the following formula:

wherein R is a linear aliphatic. saturated or unsaturated. hydrocarbon group containing 6 to 24 and preferably 10 to 18 carbon atoms and y is a hydrogen or hydroxyl group. Illustrative of the compounds defined by the above formula are the following alcohols: octyl. decyl. dodecyl (lauryl). tetradecyl (myristyl). hexa decyl (cetyl). octadecyl (stearyl). eicosyl. undecylenic. oleyl. linolyl and glycols such as 1.2-dodecanediol. 1.2- hexadecanediol and 1.2-octadecandiol. Additionally. mixtures of the above alcohols may be used including for example. well-known commercial mixtures such as Alfol 1214 (55% ofC' 43% of C Alfol 1216 (61% of C 26% of C 11% of C Alfol 1218 (40% of C 30% of C 20% of C 10% of C t). all produced by Continental Oil Co. and Neodol 25 (23% of C 25% of C 31% of C and 21% of C produced by the Shell Chemical Co.

The solvents which may be used in the method of this invention generally include any solvent which is polar. non-reactive and miscible with the selected alcohol. glycidol and the reaction product. It is also preferable that the selected solvent be volatile at reaction temperature. While any solvent having the above-indicated properties may be used. the preferred solvents are the ketones (with basic catalyst) and ethers (with acid or basic catalyst). and more particularly. dialkyl ketones having 4 to 8 carbon atoms and the mono and polyethers having 3 to 12 carbon atoms. Illustrative of such compounds are the following: methyl ethyl ketone. methyl propyl ketone. methyl isobutyl ketone. diethyl ketone. dipropyl ketone. dibutyl ketone. dioxane. eth' ylene glycol dimethyl ether. diethylene glycol dimethyl ether (diglyme). triethylene glycol dimethyl ether (triglyme). dipropyl ether and dibutyl ether. Other compounds suitable for use as solvents in this invention include the amides (with basic catalyst). the dioxolanes (with basic catalyst) and the formals (with basic catalyst) and more particularly the amides of the formula:

N C M where R R and R represent independently selected alkyl groups having a combined total of 2 to 12 carbon atoms or are hydrogen atoms; dioxolanes of the formula:

R-CH-O R3 1 ng-ca-o m.

where the R groups are independently selected alkyl groups having a combined total of 3 to 8 carbon atoms or are hydrogen atoms and the formals of the formula:

R OCH O R the above compounds are illustrative of the solvents which may be used in this invention. it is emphasized that any compound having all the desired characteristics. indicated above. may suitably be used.

As noted above the monoand polyethers having 3 to 12 carbon atoms may be used with acid (as well as basic) catalyst. The useful ethers include the dialkyl ethers and the dialkyl ethers of alkylene glyeols and cyclic ethers such as dioxane (e.g. 1.4- and 1.3-dioxane) and pyran (e.g. a; y; 2,3- and 3,4-dihydropyran and tetrahydropyran). Other useful cyclic ethers include dibenzo-l 8-crown-6 and dicyelohexayl- 1 8-crown-6.

The basic catalyst which may be used includes the alkali metal hydroxides. e.g. sodium hydroxide. potassium hydroxide and lithium hydroxide". the alkali metals. e.g. sodium and potassium and the alkali metal a1- koxides such as sodium methoxide and potassium ethoxide. The particularly preferred basic catalyst is potassium hydroxide.

The acid catalyst which may be used can be any of the Lewis type acids which are known to be active in Friedel-Crafts type reactions. Suitable catalysts of this nature are listed. for example. by G. Olah in Friedel- Crafts and Related Reactions" published by lntersciencc Publications. 1963-64. Included are BF;, and its etherates such as BF 'Et O. SnCl TiCl SbCl HF. AlCl Al(C ,H A1Br FeCl ZnCland ZnBr with the preferred catalyst embodiment being the BF3'Et2O (called boron trifluoride etherate or boron trifluoride diethyl ether). The Lewis acids may also be advantageously used in combination with co-catalysts. for example. H O. HCl. HCOOH and CH COOH.

Generally the molar ratio of glycidol to selected alcohol will vary widely. More particularly a ratio of 4:1 to 14:1 moles of glycidol per mole of alcohol and preferably 6:1 to 12:1 is used. Generally. the use of a lower mole ratio will result in products having very low water solubility and the use of a higher mole ratio will result in products being too highly hydrophilic and not having the desired surface and wetting properties.

The concentration of glycidol in the selected solvent may be from 1 to 95% by weight and preferably from 5 to 15% by weight.

The amount of catalyst used will generally vary from 1 to 15% by weight based on the amount of selected alcohol charged and preferably will vary from 3 to 12%.

The temperature at which the reaction is carried out will vary widely but more particularly will depend on the type catalyst being used. When using a basic catalyst. the temperature will generally vary 125to 175C. and preferably from 140 to 160C. When using an acid catalyst, the temperature will generally vary from to 125C. and preferably from 40 to 75C.

The compounds and method of this invention are further illustrated by the following examples.

EXAMPLE 1 Alfol 12 l4 (4.90 g., 25 mmoles) and powdered KOH (0.54 g.) were charged into a 50 cc. three-neck flask fitted with stirrer. additional funnel. 6 inch Vigreaux column and distillation head. The well-stirred reaction mixture was heated with an oil bath to 150 to 155C. under a slow N purge. Methyl ethyl ketone (MEK) solution (180 g.) containing pure glycidol (19.24 g.. 99.2% assay; 260 mmoles) was added dropwise over 2.5 hours. MEK was distilled out continuously during the reaction. The distillate contained 1.0 mmoles of Solvent Cloud Point. C.

water 259 NaC 1 100 30% NaOH 100 The surface properties (at 25C.) of a 0.1% aqueous solution of the product were as follows:

Surface Tension. dynes/cm. lnterfacial Tension. dynes/cm.

EXAMPLE 1] Alfol 1214 (4.91 g.. 25mM) and KOH (0.52 g.) were reacted at C. as described in Example 1 with crude glycidol in MEK solution (238 g., 261 mM epoxide). Addition time was 3 hours. The distillate contained 10 mM epoxide. After addition of crude glycidol solution and complete reaction of glycidol (followed by epoxide analysis), the volatiles were stripped out with a stream of N The product contained 2.4% unreacted Alfol 1214 (determined chromatographically). Thus 88% of the Alfol 1214 was utilized resulting in an 11.4 to 1 mole adduct of glycidol to alcohol. The product was refluxed with 150 cc. hexane for 1 hour using vigorous stirring. After cooling. the hexane layer was decanted and vacuum stripped; wt. 1.4 g. The product was freed of hexane under vacuum. The solvent-free purified product exhibited the following cloud points as a 1% solution:

Solvent Cloud Point. C.

water 100 259? NaCl 100 30% NaOH 100 The surface properties (at 25C.) of a 0.1% aqueous solution of the product surfactant were as follows:

Surface Tension. dynes/em.

lnterfacial Tension. dynes/cm.

EXAMPLE 111 with aqueous NaOH and vacuum stripped: wt. residue 23 g. The residue was extracted with hexane as described in Examples I and 11. The stripped extract weighed 2.8 g. and contained 22% Alfol 1214. Thus 87% of the Alfol 1214 had reacted with glycidol to 5 form a surfactant having a 11.5 to 1 mole adduct of glycidol to alcohol. The product was freed of solvent under vacuum. A 1% aqueous solution of the product had a cloud point 100C. The product was soluble in 25% NaCl and 30% NaOH. The surface properties (at 25C.) of a 0.1% aqueous solution of the surfactant were as follows:

Surface Tension. dynes/cm. 27.6 5 lnterfacial Tension. dynes/cm. 2.4 Draves Wetting l'ime. secs. 77

EXAMPLE 1V water (54 g.. 3 moles) and heated to reflux. Added 10 drops of concentrated H SO, and began to distill out acetone. Ethanol 125 cc.) was added slowly in order to maintain an homogeneous solution. A total of 250 cc. of distillate was removed (head temperature 80C.).

Flashedoff residual ethanol and water at C. using water aspirator; wt. residue 53 g. The crude product was probably sufficiently pure for use in further reac tions. Dissolved the crude product in 300 cc. hot methanol. neutralized with 50% NaOH. filtered and chilled to 25C. Filtered and vacuum dried solids; wt. 22 g.. OH No. 414 (calculated) 416. Concentrated the filtrate to 150 cc.. chilled. filtered and vacuum dried solids; wt. 20 g. Filtrate was stripped of MeOH and solids vacuum dried. The recrystallized C, diol (10.52 g., 40mM) and KOH (0.35 g.) were reacted at 150C. with redistilled glycidol (14.8 g., 200 mM. 99.2% assay) dissolved in cc. MEK using the same apparatus described in Example 1. Addition time was 1 /2 hours at a reaction temperature of 2 5C. No

epoxide remained at the end of the addition. Chro- 50 matographic analyses showed 100% of the alcohol had reacted to form a 5 to 1 mole adduct of glycidol to alcohol. The residual MEK was stripped-off under vacuum. A 1% solution of the surfactant was soluble in water.

25% NaCl and 30% NaOH with cloud points 100C. in these solution A 0.1% aqueous solution of the product had the following surface properties (at 25C.):

Surface Tension. dyues/cm. 26.5 lnterfacial Tension. dynes/cm. 3.1 Wetting Time. secs.

EXAMPLE V 65 Alfol 1214 (98 g., 0.5 moles) containing KOH (1.7 g.) was heated to 135C. Glycidol (74 g.. 1.0 moles) was added dropwise over 3 hours to a well-stirred reaction mixture and such stirring was continued for an additional 30 minutes to insure complete reaction of the glycidol. After cooling. the reaction mixture was extracted. using hexane. to remove the unreacted alcohol. Ninety percent of the alcohol was recovered unre' acted. The residual product as a 0.1% aqueous solution exhibited an interfacial tension of 8.2 dynes/cm at 25C EXAMPLES Vll and VII Using similar conditions as shown in Example V. 49 g. (0.25 moles) of Alfol 1218 was reacted with 119.9 g. (162 moles) and g. (2.5 moles) of glycidol respectively. The amount of unreacted alcohol was 71% in the first preparation and 46% in the second. The two products exhibited interfacial tensions of 7.1 and 7.8 dynes/cm at 25C.

EXAMPLE Vlll Surface Tension. dynes/cm lnterfaclal Tension. dynes/cm EXAMPLE lX Alfol 1214 (1.96 g.. 10 mmoles). moles). ethylene glycol dimethyl ether 15 cc) and boron 'trifluoride etherate (0.10 cc.) was heated at 50 to 55C. with stirring. Glycidol (7.4 g.. 100 mmoles) dissolved in ethylene glycol dimethyl ether l 8 cc) was added dropwise. Gas chromatographic analysis indicated that 85% of the Alfol 1214 had reacted giving a surfactant having an 1 1.8 to 1 mole adduct of glycidol to alcohol. The unreacted alcohol was removed by extraction with petroleum ether. A 0.1% aqueous solution of the product surfactant had the following surface properties (at 25C.):

Surface Tension. dynes/cm lnterfaclal Tension. dynes/cm EXAMPLE X The same procedure as in Example lX was followed using Alfol 1218 (2.16 g. 10 mmoles) instead of Alfol 1214. Chromatographic analysis revealed that 80% 0f the alcohol had reacted yielding a product having a 12.5 to 1 mole adduct of glycidol to alcohol. The unreacted alcohol was removed by extraction with petroleum ether. A 0.1% aqueous solution of the product surfactant had the following surface properties at 25C Surface Tension. dynes/cm lnterfacial Tension. dynes/cm What isclaimed is: l. The methodfor preparing surfactants comprising reacting:

a. an aliphatic alcohol having the formula:

R CHCH OH wherein R is a linear aliphatic hydrocarbon containing 6 to 24 carbons and is a hydrogen or hydroxyl group with b. glycidol in the presence of a polar. non-reactive and miscible solvent selected from the group consisting of:

i. dialkyl ethers and dialkyl ethers of alkylene glycols having 3 to 12 carbons,

ii. dioxane and iii. pyran and a Lewis acid catalyst at a temperature of from about 25 to about l25C said glycidol and alcohol being present in a ratio of4:l to l4:l moles of glycidol per mole of alcohol.

2. The method of claim 1 wherein said Lewis acid is selected from the group consisting of BF;, BFether-ate, SnCh. TiC'l SbCl HF. AlCl;;. Al(C H,-,);,. AlBr FeCl ZnCland ZnBr 3. The method of claim 2 wherein said Lewis acid is BF etherate.

4. The method of claim 3 wherein said reaction is carried out at a temperature of from about 40 to about 75C.

5. The method of claim 4 wherein R contains 10 to 18 carbons and the molar ratio of glycidol to alcohol is from 6:1 to 12:1. I

6. The method of claim 5 wherein said Lewis acid is BF etherate.

7. The method of claim 6 wherein said solvent is selected from the group consisting of ethylene glycol dimethyl ether and l.4-dioxane. 

1. THE METHOD FOR PREPARING SURFACTANTS COMPRISING REACTING: A. AN ALIPHATIC ALCOHOL HAVING THE FORMULA:
 2. The method of claim 1 wherein said Lewis acid is selected from the group consisting of BF3, BFetherate, SnCl4, TiCl4, SbCl5, HF, AlCl3, Al(C2H5)3, AlBr3, FeCl3, ZnCl2 and ZnBr2.
 3. The method of claim 2 wherein said Lewis acid is BF3 etherate.
 4. The method of claim 3 wherein said reaction is carried out at a temperature of from about 40* to about 75*C.
 5. The method of claim 4 wherein R contains 10 to 18 carbons and the molar ratio of glycidol to alcohol is from 6:1 to 12:1.
 6. The method of claim 5 wherein said Lewis acid is BF3 etherate. 